The Art of Creating HTML Emails: A Comprehensive Guide

Crafting effective HTML emails is a unique challenge for both developers and marketers. Unlike traditional web pages, HTML emails require a distinct approach to ensure they render consistently across a variety of email clients.

This guide outlines the essential steps and best practices for building successful HTML email templates.

Master HTML Email Coding Techniques

HTML email development diverges significantly from standard web development. It’s critical to recognize the constraints posed by email clients and apply specific coding techniques:

• Use tables for layout, as many email clients don’t support div-based layouts.
• Apply inline CSS styles instead of external stylesheets, which are often stripped out by email clients.
• Avoid JavaScript and complex CSS properties, as they’re not supported in most email clients.

A collaborative approach between designers and developers from the start is key to determining the optimal design approach for your emails.

Related: The 4 Steps To Designing An Amazing Marketing Email

Prioritize Mobile-First Design

(source: litmus)

With the majority of users reading emails on mobile devices, mobile-first design should be a top priority.

Ensure your HTML emails are fully responsive and optimized for small screens:

• Utilize responsive design techniques to ensure your layout adjusts smoothly across devices.
• Create device-specific images to avoid oversized graphics on mobile.
• Increase font sizes for readability on small screens.

Pro Tip: Design mobile-specific images at double their intended width to maintain clarity on retina displays.

Use Live Text for Important Content

Whenever possible, use live text instead of embedding text within images. This approach offers several key benefits:

• Better SEO performance since text is searchable by email clients and search engines.
• Improved accessibility for users with visual impairments or those relying on screen readers.
• Ensured readability even when images are blocked or slow to load.

Navigate Outlook’s Challenges

Outlook, notorious for its lack of support for modern CSS, presents unique obstacles in HTML email development. However, there are reliable workarounds:

• Use VML (Vector Markup Language) to handle background images.
• Provide CSS fallbacks for properties unsupported by Outlook.
• Test extensively in different Outlook versions to catch rendering issues early.

Choose Web-Safe Fonts

While custom fonts can elevate your email’s design, they won’t display consistently across all email clients. To maintain a polished look:

• Stick to web-safe fonts like Arial, Helvetica, and Times New Roman.
• Set up a font stack with appropriate fallbacks to ensure consistency when custom fonts don’t load.

The following images illustrate what an email might look like without a fallback font:

Corbel custom font is used in the first image. Times New Roman is used in the second as a system default font.

Include Fallback Colors for Background Images

Not all email clients support background images, so you need to plan for this limitation:

• Ensure text remains visible if the background image fails to load, preserving readability.
• Set a fallback background color that complements your design.

The first image shows live text on a background image. When the background image is blocked we see a solid background color (second image). In this particular case we used a fallback blue color to maintain brand colors and readability.

Optimize Image Sizes

Large images can slow down email loading times, negatively impacting the user experience. To strike a balance between quality and speed:

• Optimize file size while maintaining good image quality to avoid lengthy load times.
• Limit full-width images to a maximum of 1200px in width.
• Compress images using tools like TinyPNG or ImageOptim.

Use Animated GIFs Wisely

Animated GIFs can boost engagement, but they come with challenges. Be cautious of their file size and the email clients that don’t fully support animation:

• Ensure the first frame of the GIF communicates key information, as some clients only display the first frame.
• Keep GIF file sizes manageable to ensure quick load times.
• Provide a static fallback image for clients like Outlook, which may not display animated content.

First image – animated GIF inserted in the email. The second image is what Windows Outlook users would see unless you add in your HTML code an Outlook-specific fallback image with your preferred animation frame.

Test, Test, Test!

Thorough testing is crucial to ensure your HTML email renders correctly across the wide variety of email clients and devices in use today:

• Use testing platforms like Litmus or Email on Acid to simulate your email’s appearance across different clients.
• Send test emails to actual devices and inboxes to catch any layout or rendering issues.
• Check for broken layouts, image display issues, and other potential problems before sending the final version.

Conclusion

Creating effective HTML emails requires careful attention to detail and a clear understanding of the limitations of various email clients. By following these best practices—such as using tables for layout, prioritizing mobile-friendly designs, and testing thoroughly—you’ll ensure your emails are not only visually appealing but also functional and responsive across different platforms. Consistency and readability should always be prioritized over intricate designs that may not render well for all recipients.

How Agile agency can help

As a leading London Email Marketing Agency, we are pleased to offer assistance with any of the aforementioned steps—be it design, email coding, or the management of your email marketing campaigns—or all of the above.

Our commitment to excellence is underscored by our recognition as a Top Full Service Digital Agency in the United Kingdom for 2024.